Gaza City -LRB- CNN -RRB- -- An Italian humanitarian activist and journalist who was kidnapped in Gaza has been found dead and one person is in custody , the Hamas Interior Ministry said Friday in a statement .

Police investigating the case learned where 36-year-old Vittorio Arrigoni was being held and went to the location , where they found the body , the statement said .

An autopsy revealed that he had been killed hours before police entered the location , it said .

Medical sources said his body was taken to Shifa Hospital in Gaza .

The grisly outcome came hours after a video was posted on YouTube showing a man identified by his colleagues as Arrigoni . A black blindfold covered his eyes ; his right cheek appeared red as though it had been hit ; his hands appeared to be bound behind his back . A hand belonging to someone outside of the view of the lens appeared to be grasping his hair on the back and pointing the captive 's head toward the camera .

Arabic writing scrolled over the video threatened that Arrigoni would be killed if Hesham al-Saeedni , who has been held for nearly a year by Hamas , were not released within 30 hours of 11 a.m. Thursday . Al-Saeedni is the leader of a group that may have been inspired by al Qaeda , said Alfredo Tradardi , the Italy coordinator for the International Solidarity Movement , where Arrigoni was a volunteer .

The writing calls Italy an `` infidel nation whose armies are still present in Muslim lands . ''

Tradardi , who had initially expressed optimism that his co-worker would be released unharmed , told CNN in a telephone interview that the outcome underscores the need for progress to be made toward Middle East peace . `` Now , we have to work more deeply to try to change the foreign policy of our government , of the European government , of the United States government in order that they could press Israel to solve the problem of the Palestinians . ''

Arrigoni had been active in the Palestinian cause for nearly a decade , and had been allied with the International Solidarity Movement for more than two years , `` monitoring human rights violations by Israel , supporting the Palestinian popular resistance against the Israeli occupation and disseminating information about the situation in Gaza to his home country of Italy , '' the non-governmental organization said in a written statement .

He was granted honorary citizenship for his work for the Palestinian people , the statement said .

`` Vittorio Arrigoni is a hero of Palestine , '' said a statement released by Khalil Shaheen , head of the economics and social rights department at the Palestinian Centre for Human Rights . `` He was available everywhere to support all the poor people , the victims . ''

Arrigoni 's colleagues last saw him about 8 p.m. Wednesday near the port in Gaza City , said Joe Catron , a member of the International Solidarity Movement .

`` I think he was just the first foreigner they ran across , '' Catron said about the abductors . `` It is ironic they happened to come across someone who has dedicated a part of his life to helping Palestine . ''

Arrigoni , who was also working as a freelance journalist , was from the northern Italian region of Lombardy .

Journalist Talal Abu-Rahmi , CNN 's Yasmin Amer , Tom Watkins and Erin McLaughlin contributed to this story

@highlight

NEW : Autopsy indicates he had been dead for hours before police arrived

@highlight

YouTube video appears to show the activist bound and blindfolded

@highlight

The activist and freelance journalist was from the Lombardy region in northern Italy